Stacker 3.1 for Windows and DOS - Late Breaking News

This document contains important information that is not
included in the Stacker for Windows & DOS User's Guide or in
the Stacker 3.1 Supplement. If you're using any special or
unique software with your system, such as and Super PC-Kwik
Cache, see the help provided in Setup. To get help in these
situations:

When Setting Up Stacker for Windows:

1       From any Setup screen, press F1.
2       Click Contents.
3       Press TAB to select Software Considerations and press
        ENTER.

When Setting Up Stacker for DOS:

1       From any Setup screen, press F1.
2       Press ENTER to choose the Index.
3       Press TAB to select Software Considerations and press
        ENTER.

To print the contents of this file

1       Retrieve this document into any word processor
2       Use the print feature

Contents

This document contains late-breaking information on the
following topics:

1.0     How Stacker Works

        1.1     How Stacker Compression Happens

        1.2     Compressing Data

        1.3     Establishing Access

        1.4     Compressing the Space on an Empty Disk

        1.5     How Your System Works with Stacker

2.0     The STACKER.INI File

        2.1     STACKER.INI Structure

        2.2     STACKER.INI General Syntax rules

        2.3     Editing your STACKER.INI File

        2.4     STACKER.INI General Switches

        2.5     Mounting Parameters

3.0     STACKER.INI Examples

        3.1     Single Hard Drive Example

        3.2     Multiple Hard Drive Example

4.0     Loading Stacker High

5.0     MS-DOS Command Equivalents


1.0     How Stacker Works

        After you set up Stacker on your computer, it works by
        decompressing files when you open them and compressing
        the files when you save them again. Stacker does its
        work in the background; you never notice it. Because
        Stacker compresses all your data, you have access to
        approximately twice as much disk space.

        How does Stacker do all this? When you set up Stacker,
        Setup modifies your system. This modification allows
        the operating system to "recognize" your Stacker drive.
        Prior to DOS 6, all of these changes to your system
        were contained in the CONFIG.SYS file. Now with DOS 6,
        these changes take place by "preloading" the
        information from two files, DBLSPACE.BIN and
        STACKER.INI.

        Stacker adds an extra drive to your system during
        Setup, and then compresses all your files into one
        large file on this new drive. DOS assigns this new
        drive the next available drive letter, so your data is
        really on the new drive (D, for example). Stacker then
        exchanges drive letters between your original disk (C,
        for example) and the new drive. So all your data is
        where you expect, on drive C.

1.1     How Stacker Compression Happens

        Setup does two things when it compresses the data on a
        disk. It:

        1       Compresses the data and stores it more efficiently
                to save space.

        2       Establishes access to the compressed data so your
                computer can use it.

        The compression process is the same whether you use the
        Express or Custom method.

1.2     Compressing Data

        1       Setup compresses data by creating a hidden file,
                STACVOL.DSK, in the root directory of the disk.

        2       Setup reads every file on the disk, one at a time.
                It then compresses each file and stores it
                efficiently in the new STACVOL.DSK file. As each
                file is stored and verified, Setup deletes the
                original uncompressed file, making more space on
                the disk. In the process, the STACVOL.DSK file
                gets larger and larger as more and more data is
                added to it.

        3       As it stores files in STACVOL.DSK, Setup keeps
                track of each file's size and location.

        4       Setup leaves any files the system needs for
                startup, as well as any files with the system
                attribute, outside of STACVOL. Consequently, your
                hard disk contains
                -  The large STACVOL file
                -  Some uncompressed files, including DBLSPACE.BIN
                   and STACKER.INI
                -  Some free space

        Once the files are stored,

        1       Setup runs a version of Norton Speed Disk to
                defragment STACVOL.DSK so it is in as few pieces
                as possible.

        2       Setup enlarges the STACVOL file to fill most of
                the rest of the disk, leaving a small amount of
                space uncompressed. All your new free space is
                within the STACVOL file, so it will be available
                on the stacked disk.

        3       Setup leaves about 1 MB on the uncompressed drive
                your system starts from. If it is not a "boot"
                drive, Setup it leaves about 100 KB. If you use
                custom Setup, you can leave more space
                uncompressed.

        Example

        Suppose you want to compress the data on a 120 MB drive
        containing about 80 MB of data. Express Setup creates a
        STACVOL.DSK file and compresses all the data it can
        into the file. Then it enlarges the STACVOL file to
        about 119 MB leaving about 1 MB uncompressed.

        If the disk isn't used for starting up, STACVOL.DSK
        could be larger than 119 MB.

1.3     Establishing Access

        Setup has to tell your system how to access the Stacker
        drive, so it first copies a file, DBLSPACE.BIN, to your
        system. At start up, MS-DOS 6 looks for this file
        before it looks for any other file. When it finds this
        file, it loads the Stacker driver into memory.

        Because every system is different, the Stacker driver
        is configured specifically for your system. Setup
        creates a hidden file, STACKER.INI, to handle that
        configuration. Any information found in DBLSPACE.BIN
        and configured by STACKER.INI is loaded before any
        other device drivers (which are normally found in
        CONFIG.SYS). This is called "preloading." Before DOS 6,
        data compression had to compete with every other device
        driver to load into memory. Because DOS 6 has endorsed
        data compression, there is no competition. . . Stacker
        is loaded first!

        In STACKER.INI, Setup creates lines to set the
        compression speed, specify the Stacker directory, and
        define the STACVOL file as another drive so it gets a
        new drive letter. If these lines already exist, Setup
        edits them.

        At startup time, the operating system gives the new
        drive (the STACVOL file) the next available drive
        letter. So if you compressed the data on your only hard
        disk, the drive that represents the STACVOL file gets
        named D.

        Setup adds SW to the STACVOL line. This swaps the drive
        letters so you can refer to files on drive C, just as
        you always have. The new drive letter (D) now refers to
        the uncompressed drive.

        Setup arranges to keep startup files found in both
        Stacker drives and their uncompressed drives the same.

        Example

        Using that same, single 120 MB hard disk, the following
        lines are placed in the STACKER.INI file:
        /P=1
        /DIR=C:\STACKER
        C:\STACVOL.DSK, SW

        The /P switch controls how fast Stacker compresses data
        when it puts it on the disk. You can tune Stacker later
        to change the speed to get even more compression. The
        second line tells DOS where to find the Stacker files.
        The last line loads the Stacker drive and assigns a
        drive letter. The SW exchanges the drive letters, so
        the data is still referenced by the same drive letter.

1.4     Compressing the Data on an Empty Disk

        Setup compresses the space on an empty disk very
        quickly, because it doesn't have to compress any
        existing data. It doesn't have to exchange drive
        letters either, because no current data is affected by
        the new drive letter. Setup lets you choose to compress
        only the free space if you wish. This is an excellent
        way to prepare an empty hard disk for use.

        You can compress the data on floppy disks and
        removables also. Either run Setup from the Stackometer
        in Windows or use the Stacker Toolbox to compress
        floppies as described in your documentation. All of the
        necessary statements are added to your STACKER.INI file
        to recognize removable drives as Stacker drives at
        start-up.

1.5     How Your System Works With Stacker

        When an application reads data from a Stacker drive,
        Stacker intercepts the read request and decompresses
        the data, then passes it on to the application. Because
        the data is compressed, the system doesn't have to read
        as much data, so in most cases you won't even notice
        the time it takes to decompress data. When an
        application writes data to the Stacker drive, Stacker
        again intercepts the data, compresses it, and writes it
        to the Stacker drive. The data is always compressed
        when on the disk, and is always uncompressed when in
        memory or in use by another application.

        Once Stacker has been set up on your disk, you use it
        as before. When you read data from the disk, Stacker
        decompresses the data. When you write it back to the
        disk, Stacker compresses it again. Normally, you don't
        even notice the process.

2.0     The STACKER.INI File

        The STACKER.INI file contains the configuration
        information for your Stacker device driver. It also
        specifies the drive letter assignments for your Stacker
        drive(s). This file is a hidden file located in the
        root directory of your boot drive. Setup creates the
        STACKER.INI file for you. It is updated each time you
        compress additional drives (except floppies).

        NOTE: Normally, you won't need to edit this file. Setup
        automatically takes care of the configuration for you.
        The following information details the structure of the
        file and the elements you may find in it.

        For an example of a sample STACKER.INI file, see
        STACKER.INI Example. For more detailed information,
        continue reading.

2.1     STACKER.INI Structure

        The structure of the STACKER.INI file is very simple.
        Each statement or switch is contained on an individual
        line. All switches are found at the beginning of the
        file, while all of the drive specifications are found
        at the end. Unlike CONFIG.SYS, this file is not
        processed on a line-by-line basis, so the order of the
        switches is not important. However, the order in which
        the drive specifications are found will be the order in
        which they are set up.

2.2     STACKER.INI General Syntax Rules

        A line can have a maximum of one item, except for
        STACVOL line mounting parameters RP, SW, and NS. These
        items are always the second item on a line. Spaces and
        tabs are allowed before or after an "=", but not after
        a "/". All text is not case-sensitive.

        You may want to modify the STACKER.INI file to change
        switches are cause other effects. All of the switches
        do not need to be included in the file. Again, Setup
        determines the appropriate ones.

2.3     Editing Your STACKER.INI File

        The STACKER.INI file is a hidden file contained in the
        root directory of your uncompressed boot drive. You may
        either change the hidden attribute and then edit it
        with any text editor, or use the STACKER.INI editor
        provided by Stac. Procedures for using this editor are
        outlined below.

        1       Insert Stacker Disk 1 into drive A or B

        2       Change to the floppy disk drive by typing its
                letter followed by a colon, for example, A: and
                press ENTER.

        3       From the DOS prompt, type STACKER and press ENTER.

        4       Note the drive letter of the uncompressed drive.

        5       From the DOS prompt, type \TOOLS\STACINI drive:
                where drive: is the letter of the uncompressed
                drive.

        6       When the lines of the file appear, edit as
                required (see the switches in the following
                section).

        7       Press Ctrl-Z to save the file.

        8       Restart your computer to put these changes into
                effect.

2.4     STACKER.INI General Switches

        The following section details each of the switches
        which may be found in the STACKER.INI file.

        *       Reserves a drive letter.

        /-AUTO  Turns off automounting for all replaceable
                drives. This saves about 2.7 KB in the driver.

        /BD=x   Specifies the base drive letter (x) from
                which to start Stacker drives. For example, if the
                first Stacker drive should be assigned to drive
                letter F, this statement would read /BD=F

        /C or /C=n  Specifies the cluster size, if necessary.
                These count as the same switch, so only one should
                be found.

        /DIR=<stacker path>  Specifies the path where the
                Stacker software is located. This switch generally
                occurs at the top of the STACKER.INI file.

        /EMS    Indicates that Stacker's disk cache (up to 64
                KB) should be stored in expanded memory, if there
                is any available.

        /M=nnn  Sets the cache memory size to nn KB. Use any
                value between 1 and 64. The amount of driver
                memory required increases by whatever you specify
                up to a maximum of 64 KB for the cache (The /M
                switch has no effect if you use it with /EMS.)

        /P=n    Sets the compression tuning. Use any value
                between 0 and 9. 0 turns compression tuning off;
                it decreases memory requirements by 4.4 KB. You'll
                have to restart your system to take advantage of
                any change in tuning if you change between 0 and
                any other value. If no /P switch is included,
                Stacker uses /P=1 for everyday usage.

                Values 0 and 1 are the fastest, with standard
                compression. 9 gets the best compression but takes
                a bit longer. Setup uses level 9 to get the best
                possible compression while setting up your Stacker
                drive.

        /RP=n   Sets the number of replaceable drives to reserve.

        /W-     Disables Windows permanent swap file pointer
                updating. By default, if Stacker detects a Windows
                permanent swap file on a disk that was swapped,
                Stacker searches through its preset pattern for
                the Windows directory and places the full path of
                the Windows permanent swap file in SPART.PAR in
                the Windows directory. Once this is done (the
                first time you restart your system after
                compressing the disks that contain the permanent
                swap file), it really doesn't have to be done
                again unless you make drastic changes to your
                system. If you add this switch to the STACKER.INI
                file, the search won't take place and you'll save
                a bit of time at startup.

                NOTE: Stacker checks for a Windows permanent swap
                file every time you restart your system. You can
                include the /W- switch to shorten startup time
                even if you don't have Windows.

        /W=<directory>  Names the directory that contains your
                permanent swap file pointer (SPART.PAR). Use this
                switch if your directory has an unusual name or
                isn't on the default path that Stacker searches.
                If Windows can't find its permanent swap file
                after you compress a disk, add this switch and
                restart your system. This switch tells Stacker
                exactly where to find the SPART.PAR file, saving a
                bit of time on startup. Replace it with /W- after
                Windows finds its swap file.

        /W+<directory>  Names the directory that contains your
                permanent swap file. Use it if your directory has
                an unusual name or isn't on the default path that
                Stacker searches. It causes Stacker to search its
                regular default path and find this one too, just
                in case you have multiple swap files. This switch
                actually lengthens the search, but ensures that it
                finds all the files.

2.5     Mounting Parameters

        The following parameters appear after a STACVOL
        statement. These parameters specify the mounting method
        for the Stacker drive. They are preceded by a comma
        ",".

        RP      Mount replaced.

        NS      Mount un-swapped, using the next available drive
                letter.

        SW      Mount swapped, using the next available drive
                letter.

        Multiple Swapping. /SW = jk mn xy
        After mounting all drives, swap drive pairs J: with K:,
        M: with N:, X: with Y:, and so on. You may have no more
        than 26 swaps. This option is rarely used since the
        mounting parameter "sw" on the STACVOL line handles
        standard swapping. The /SW = switch appears at the TOP
        of the file along with the other switches, however,
        swapping will not happen until all the drives have been
        mounted.

        For examples of a sample STACKER.INI files, see
        STACKER.INI Examples.

3.0     STACKER.INI Examples

3.1     Single Hard Drive Example

        In this example, the original system configuration has
        just one hard drive. EMS is available. The STACKER.INI
        file created by Express Setup would look like the
        following:

        /DIR=C:\STACKER
        /P=1
        /EMS
        C:\STACVOL.DSK,sw

        The first line specifies the directory where the
        Stacker files are located. The second line sets up the
        default compression tuning for the fastest speed with
        standard compression. /EMS tells Stacker to use
        expanded memory. The last line specifies the location
        of the Stacker drive. It then swaps the drive letter
        references so that all of the compressed data is found
        on drive C, and the uncompressed drive is referenced by
        D.

3.2     Multiple Hard Drive Example

        In this second example, the system is a bit more
        complex. This system also has expanded memory. It also
        has a combination of five hard drives (including
        removable drives). The STACKER.INI file for this
        configuration might look like:

        /DIR=C:\STACKER
        /P=5
        /EMS
        /RP=2
        /BD=I
        /SW  FM
        C:\STACVOL.DSK,sw
        D:\STACVOL.000,ns
        *
        E:\STACVOL.DSK,sw
        F:\STACVOL.000,ns
        G:\STACVOL.DSK,rp

        Again, the first line gives the location of the Stacker
        files while the second provides the compression tuning
        information. In this case, the user modified the tuning
        (from the Stacker Tuner) to the setting "More
        compression and a bit less speed." This returns a value
        of /P=5. /EMS tells Stacker to use expanded memory.
        /RP=2 reserves two replaceable drive letters, while
        /BD=I specifies that the first Stacker drive letter
        assignment is 'I". The next line, /SW=FM swaps drive F
        with drive M after all of the drives are mounted.

        The next section sets up the Stacker drives and the
        drive letter assignments. Note that Stacker always
        takes the next available drive letter. Remember that
        there were five drives originally (C-G). This means
        that H is the next logical drive letter assignment.
        However, since the switch /BD=I is present, the first
        drive letter assignment has to be I. The following
        explains the drives and their assignments.

        C:\STACVOL.DSK, sw
        The Stacker drive becomes drive C, and the uncompressed
        drive (originally C) becomes the next available drive
        letter, I.

        D:\STACVOL.000,ns
        Because of the "ns" mounting parameter, the Stacker
        drive is not swapped and is assigned drive letter J,
        while the uncompressed drive remains D.

        *
        Reserves the next drive letter, K.

        E:\STACVOL.DSK,sw
        Again swaps the drive assignments. The Stacker drive
        remains E, while the uncompressed drive becomes L.

        F:\STACVOL.000, ns
        Because of the "ns" mounting parameter, the Stacker
        drive is not swapped and is assigned drive letter M,
        while the uncompressed drive remains D. Note: after all
        of the drives are mounted, F and M will be switched due
        to the line /SW FM.

        G:\STACVOL.DSK, rp
        RP specifies that the drive letter of the uncompressed
        drive is assigned to the Stacker drive (G). There is no
        drive letter assigned to the uncompressed drive. Any
        data on it becomes unavailable after mounting.

        After completing all of the assignments in STACKER.INI,
        here are all of the drives and their types:
        C       Stacker drive
        D       Uncompressed drive containing the STACVOL file for
                Stacker drive J
        E       Stacker drive
        F       Stacker drive (note that it is only switched once
                the line /SW FM is executed)
        G       Stacker drive
        H       DOES NOT EXIST
        I       Uncompressed drive containing the STACVOL file for
                Stacker drive C
        J       Stacker drive
        K       Reserved by the * (no data can be found here)
        L       Uncompressed drive containing the STACVOL file for
                Stacker drive E
        M       Uncompressed drive containing the STACVOL file for
                Stacker drive F (note that it is only switched
                once the line /SW FM is executed)


4.0     Loading Stacker High

        Stacker provides a device driver, STACHIGH.SYS,  which
        loads the Stacker device driver into either the high
        end of DOS memory, or to the Upper Memory Blocks (UMB).

        To load Stacker high with MS-DOS 6

        1       Edit your CONFIG.SYS file

        2       Place the following line in the file
                DEVICEHIGH=STACHIGH.SYS

        3       Save your CONFIG.SYS file

        4       Restart your system for the changes to take
                effect.

        STACHIGH.SYS obtains its configuration information (for
        the Stacker device driver) from STACKER.INI, so there
        are no switches.

        To load Stacker high with other memory managers,
        consult your memory manager's documentation. Use
        STACHIGH.SYS as the specified device driver.

5.0     MS-DOS Command Equivalents

        If you type in a compression-related DOS command on a
        Stacker drive, the command is automatically run. There
        is no need to know both the DOS and Stacker commands.
        However, some users want to know the equivalents, so
        this section is provided.

        DOS Command                     Stacker Equivalent

        CHKDSK (and all parameters)     CHECK (and same
                                        parameters)

        DBLSPACE/CHK                    CHECK

        DBLSPACE/DEF                    SDEFRAG

        DBLSPACE/LIST                   STACKER

        DBLSPACE/MO drive:              STACKER drive:

        DBLSPACE/U drive:               STACKER -drive:

        DIR/C                           SDIR
        DIR/C/P                         SDIR/P
        DIR/C/H                         SDIR/H
        DIR/C/W                         SDIR/W

        DEFRAG                          SDEFRAG
        DEFRAG/F                        SDEFRAG
        DEFRAG/U                        SDEFRAG/Q
        DEFRAG/B                        SDEFRAG
        DEFRAG/SN                       SDEFRAG/SN
        DEFRAG/SE                       SDEFRAG/SE
        DEFRAG/SD                       SDEFRAG/SD
        DEFRAG/SS                       SDEFRAG/SS
        DEFRAG/LCD                      SDEFRAG/M
        DEFRAG/BW                       SDEFRAG/M
        DEFRAG/CO                       SDEFRAG
        DEFRAG/SKIPHIGH                 SDEFRAG

        FORMAT/S                        Stacker-Aware copy of
                                        DBLSPACE.BIN is placed on
                                        formatted disk.

        SYS                             Stacker-Aware copy of
                                        DBLSPACE.BIN is placed on
                                        formatted disk.

